Starter battery on shore power

[frahkn]

I hijacked the “Generator” thread, with a question (thanks for the three replies), earlier today but have started this instead so that I can provide some background.

I replaced my cheap, basic domestic battery bank last year (with another cheap, basic set) but didn’t change the starter battery. It had always started first time in the 5 years I have owned the boat.

During this summer’s boating the starter battery was fine all trip but then, as I was coming home:-

On one day there was a slight reluctance to start. Afterwards I cruised for 8 hours.
On the next day it took two or three attempts to get the engine started but again we cruised for several hours.
On the 3rd day the engine only just started, I was not too far from home so I ran 10 hours and got back to the marina and plugged into the shore-power.
On the next day there was absolutely nothing when key is turned. I remained on shore power all day while we packed and cleaned the boat but nothing changed..

I left things to the yard to sort out as I had to get home, as I wouldn’t be moving the boat again till spring, they have not got round to this yet but that’s fine, I am in no hurry.

I have not had the boat from new but I understand that the original electric work was done by Guy Taylor when he was with Orion.

I have a Beta 43 with the usual 2 alternators, a Stirling battery management system and a Mastervolt 12/2500 combi.
I had always thought that this would charge the domestic batteries and the starter battery when on shore power. However the fitter at the yard told me that this would be an unusual arrangement and that normally the charger only charges the domestic bank via shore power. The starter must usually rely solely on the alternator. 

The fitter is a decent and reliable guy but admits that his speciality is not electrics and that he could be wrong.

Obviously charger can be wired different ways but how common is this arrangement? Also, what other explanation could there be?

I am not on the boat at the moment but can probably provide some more detail if required.

Sorry this is so long but I wanted to provide the relevant detail. 
 

[nicknorman]

The fitter is wrong. The Combi has a separate charging output for the engine battery, 6A maximum IIRC. Of course it could be that no-one bothered to run a wire from the Combi to the engine battery, but it would be wrong to say that was normal.

Your problem is nothing to do with whether the starter battery gets charged by the Combi. Either the engine battery is totally knackered, or the engine alternator /wiring is faulty. Or I suppose some problem with the wiring between the starter battery and the starter motor, eg a dodgy battery isolator switch.

Do you have a voltmeter on the Beta panel? If so, it shows the engine battery voltage and you would be able to see if the engine alternator was charging (voltage around or above 14v).

Its best not to guess these things, easy to take some simple measurements with a voltmeter to determine where the problem lies, and then fix it. Rather than randomly replacing things until you hit the problem! 

[frahkn]

1 hour ago, nicknorman said:

The fitter is wrong. The Combi has a separate charging output for the engine battery, 6A maximum IIRC. Of course it could be that no-one bothered to run a wire from the Combi to the engine battery, but it would be wrong to say that was normal.

Your problem is nothing to do with whether the starter battery gets charged by the Combi. Either the engine battery is totally knackered, or the engine alternator /wiring is faulty. Or I suppose some problem with the wiring between the starter battery and the starter motor, eg a dodgy battery isolator switch.

Do you have a voltmeter on the Beta panel? If so, it shows the engine battery voltage and you would be able to see if the engine alternator was charging (voltage around or above 14v).

Its best not to guess these things, easy to take some simple measurements with a voltmeter to determine where the problem lies, and then fix it. Rather than randomly replacing things until you hit the problem! 

Thanks for your reply.

I do have a voltmeter, as part of the Stirling battery management but although it has 4 channels, only one is wired up, the domestic batteries.

I also suspect the alternator but am confused about 3 things:-

*  Can a battery go from working perfectly to completely flat in 3 starts?

*  If it were the isolator switch, would it not be off (I couldn't start at all) or on (things would be fine) - this is not what I experienced.

*  Either way, wouldn't the time on shore-power put enough back in the battery to at least turn the engine over if not start it?

I am confident that the yard will fix things but I have had the boat for 5 years and it's about time that I tried to understand more of what's going on with it.

[1st ade]

4 hours ago, frahkn said:

Can a battery go from working perfectly to completely flat in 3 starts

They certainly can in a car.

One of our vehicles died last year - one start normal, next struggled, next wouldn't even light the warning lights (21 year old diesel so no fancy electronics).

Left on charge all night - lights were OK; still wouldn't turn engine (at all)

[Jen-in-Wellies]

They can in a boat too. Starts ok one day. Next day is a bit hesitant and slow. The day after, completely dead. In this case it was the engine start battery.

Another question. Does the engine have one alternator, or two? If two, then the house and engine start circuits are most likely separate. If one, then the alternator is switched either via a manual switch to either the house, start, or both battery banks, or via a special voltage sensing relay, or with diodes. More modern narrowboats tend to use the twin alternator and seperate engine and house system approach, but split charging from one alternator is common. A fault in the switch, or relay could prevent the start battery chàrging.

Mostt likely it is the battery, but there are other possibilities. Needs to be checked out with a multimeter, engine off and engine running to narrow it down.

Jen

[Rob-M]

You could try jump starting the engine from the domestic batteries then measure the charging voltage on the starter battery to see whether it is charging with the engine running.  As Nick said there should be a voltage around\above 14v on the starter battery with the engine running.  If there is a reasonable charging voltage run the engine for a while then when you stop the engine take some regular readings from the starter battery to see if it is holding a charge.

[Tony Brooks]

I think Nick is talking about a portable voltmeter as per a multimeter because you need to take measurements at a variety of points in the system.

For example:

Battery pos to battery neg (lead post/stud) expect 12V plus. If lower charge.

Ditto try to spin starter - expect 10V plus, if  less charge, retry, if the same faulty battery, if 10V plus next step

Now at battery clamps/terminals and as above but if the voltage is less that 10V remove and clean the connection, make sure they are tight.

Now between the master switch terminals. Ignore any reading until you try to start it. Expect maybe 0.5 volt but if more the switch is suspect, if several volts the switch is faulty.

That tests the "usual suspects" so now to test the circuit.

Voltmeter between battery pos and main starter pos terminal, ignore reading, try to start. Expect a very few 10ths of a volt more that across masters witch. If  more there is a loose/dirty connection or undersized wiring between battery & starter (on a Beta look for the positive "bus bar" stud on the engine bearer.)

Now move to the terminal where the current goes into the starter motor if possible and try to start. While starting the reading should be a fraction more than above, if several volts suspect faulty solenoid contacts (may not be appropriate on a Beta, not sure - too hard to see).

Now battery negative to starter negative/starter body. Ignore any reading and try to start. If the meter reads more than about 0.3V then there is a problem with the negative part of the circuit.

 

[nicknorman]

5 hours ago, frahkn said:

Thanks for your reply.

I do have a voltmeter, as part of the Stirling battery management but although it has 4 channels, only one is wired up, the domestic batteries.

I also suspect the alternator but am confused about 3 things:-

*  Can a battery go from working perfectly to completely flat in 3 starts?

*  If it were the isolator switch, would it not be off (I couldn't start at all) or on (things would be fine) - this is not what I experienced.

*  Either way, wouldn't the time on shore-power put enough back in the battery to at least turn the engine over if not start it?

I am confident that the yard will fix things but I have had the boat for 5 years and it's about time that I tried to understand more of what's going on with it.

I suppose the thing I’m not clear about is exactly what the “sterling battery management” thingy actually does. Does it combine the output of both alternators? And have some sort of split charge system? Or is it just applied to the domestic alternator?

Anyway yes, starter batteries can fail quickly. It is perhaps a 110Ah battery but to start an engine like a Beta takes less than 1AH, so it can be extremely knackered and still start the engine satisfactorily. It is only when the final straw breaks the camels back that it suddenly won’t start it.

So most likely the alternator is fine and the battery dead. But just possibly, the alternator is defective and the Combi engine battery charging wire isnt wired up. The latter is much less likely though.

On the point about the isolator, they can and often do fail with high resistance due to dirty or poor contacts. With something like a starter motor which takes a very large current, a modest extra resistance generates a lot of local heat that can melt the plastic switch body and burn contacts further, so it can degrade quickly.

So as I said earlier, there are several possible fault scenarios and only by testing can the right one be identified.

[Tony Brooks]

Tha'ts the problem Nick, not enough detail. A  Sterling management systems might be a simple  controller for a single alternator or it might be an A to B that does combine/split inputs and outputs. Once again more info required from the OP

[MtB]

42 minutes ago, nicknorman said:

So most likely the alternator is fine and the battery dead. But just possibly, the alternator is defective and the Combi engine battery charging wire isnt wired up. The latter is much less likely though.

 

One thing puzzling me here is why the Combi engine battery output would ever be wired up on a twin alternator boat. Surely the dedicated engine battery alternator will charge the engine battery just fine with no assistance from Mr Sterling's gubbins, just as it does on a car. 

On reflection, I don't actually understand what a 'combi' is!

[Tony Brooks]

20 minutes ago, Mike the Boilerman said:

 

One thing puzzling me here is why the Combi engine battery output would ever be wired up on a twin alternator boat. Surely the dedicated engine battery alternator will charge the engine battery just fine with no assistance from Mr Sterling's gubbins, just as it does on a car. 

On reflection, I don't actually understand what a 'combi' is!

Its the inverter - battery charger. Not the Sterling thing in this case.

[nicknorman]

26 minutes ago, Mike the Boilerman said:

 

One thing puzzling me here is why the Combi engine battery output would ever be wired up on a twin alternator boat. Surely the dedicated engine battery alternator will charge the engine battery just fine with no assistance from Mr Sterling's gubbins, just as it does on a car. 

On reflection, I don't actually understand what a 'combi' is!

You are confusing the sterling battery management thing, with the Mastervolt Combi. The latter is an inverter/charger, providing mains from the battery or charging the battery from the mains. The idea of wiring it to the engine battery is so that when the boat is left on shore power for long periods  the engine battery is kept trickle charged. It has a dedicated low current output designed for the engine battery.

[WotEver]

I suspect that the ‘Sterling Battery Management’ thingy is their equivalent to a BMV. In other words an Ah counter with one or more shunts.

Not an alternator controller. 

But of course, I could be wrong. 

[WotEver]

The fact that whoever installed the battery monitor apparently didn’t run a wire from the starter battery up to it suggests to me that they might also not have bothered to wire the charger to the starter battery either. It makes little sense not to as it wouldn’t be a particularly fat cable and it would follow the same run as the main output but the reasons some folk do stuff has often escaped me. 

[Alan de Enfield]

9 hours ago, frahkn said:

However the fitter at the yard told me that this would be an unusual arrangement and that normally the charger only charges the domestic bank via shore power

As I stated on the 'other thread', this method of wiring is not 'unusual', I have had two boats wired in such a fashion - why ? I have no idea.

The chargers commonly have the ability to charge 2 or 3 battery banks, and often an additional specific low-current (typically 5a) specific starter-battery output. The installers often / occasionally obviously just don't bother to connect them.

The Victron Centaur that recently burnt-out had 3 outputs, whilst its replacement, the Victron Phoenix has 2 outputs + A starter battery output.

But it is important to remember that the charger output is split across the number of outputs (except for the starter output which is separate)

 

[WotEver]

That’s a very confusing schematic in black & white - it appears to show the starter charge feed going to the negative terminal. 

[Alan de Enfield]

9 minutes ago, WotEver said:

That’s a very confusing schematic in black & white - it appears to show the starter charge feed going to the negative terminal. 

Sorry - I scanned it quickly and didn't set the colour option. When I scan it in colour the forum message is "above 7mb have ignored it"

The 'colours' are a very faint purple, 

The Starter battery 'heavy black' lead goes to "trickle charge - " terminal, and the very pale purple one (with the 25 amp fuse) goes to the "trickle charge +" terminal.

 

 

Edited January 30, 2018 by Alan de Enfield

[MtB]

27 minutes ago, nicknorman said:

You are confusing the sterling battery management thing, with the Mastervolt Combi. The latter is an inverter/charger, providing mains from the battery or charging the battery from the mains. The idea of wiring it to the engine battery is so that when the boat is left on shore power for long periods  the engine battery is kept trickle charged. It has a dedicated low current output designed for the engine battery.

 

Ah I geddit now. Thanks Nick.

[frahkn]

3 hours ago, Jen-in-Wellies said:

They can in a boat too. Starts ok one day. Next day is a bit hesitant and slow. The day after, completely dead. In this case it was the engine start battery.

Another question. Does the engine have one alternator, or two? If two, then the house and engine start circuits are most likely separate. If one, then the alternator is switched either via a manual switch to either the house, start, or both battery banks, or via a special voltage sensing relay, or with diodes. More modern narrowboats tend to use the twin alternator and seperate engine and house system approach, but split charging from one alternator is common. A fault in the switch, or relay could prevent the start battery chàrging.

Mostt likely it is the battery, but there are other possibilities. Needs to be checked out with a multimeter, engine off and engine running to narrow it down.

Jen

Two alternators.

Adverc thingy for splitting the charge.

No chance of engine running I'm afraid.

3 hours ago, Rob-M said:

You could try jump starting the engine from the domestic batteries then measure the charging voltage on the starter battery to see whether it is charging with the engine running.  As Nick said there should be a voltage around\above 14v on the starter battery with the engine running.  If there is a reasonable charging voltage run the engine for a while then when you stop the engine take some regular readings from the starter battery to see if it is holding a charge.

Alas the domestic and the start batteries are too far apart for me to do this with "ordinary" jump leads. It's just occurred to me that this may be why the combi is not linked to the start battery - if it's not.

[frahkn]

3 hours ago, Tony Brooks said:

I think Nick is talking about a portable voltmeter as per a multimeter because you need to take measurements at a variety of points in the system.

For example:

Battery pos to battery neg (lead post/stud) expect 12V plus. If lower charge.

Ditto try to spin starter - expect 10V plus, if  less charge, retry, if the same faulty battery, if 10V plus next step

Now at battery clamps/terminals and as above but if the voltage is less that 10V remove and clean the connection, make sure they are tight.

Now between the master switch terminals. Ignore any reading until you try to start it. Expect maybe 0.5 volt but if more the switch is suspect, if several volts the switch is faulty.

That tests the "usual suspects" so now to test the circuit.

Voltmeter between battery pos and main starter pos terminal, ignore reading, try to start. Expect a very few 10ths of a volt more that across masters witch. If  more there is a loose/dirty connection or undersized wiring between battery & starter (on a Beta look for the positive "bus bar" stud on the engine bearer.)

Now move to the terminal where the current goes into the starter motor if possible and try to start. While starting the reading should be a fraction more than above, if several volts suspect faulty solenoid contacts (may not be appropriate on a Beta, not sure - too hard to see).

Now battery negative to starter negative/starter body. Ignore any reading and try to start. If the meter reads more than about 0.3V then there is a problem with the negative part of the circuit.

 

Very useful stuff Tony, I'll save it all for next time I'm on the boat. Thanks very much, practical advice is what I need even though the yard will fix the problem in this particular case.

I do worry that I should know more about my own boat.

[frahkn]

3 hours ago, Tony Brooks said:

Tha'ts the problem Nick, not enough detail. A  Sterling management systems might be a simple  controller for a single alternator or it might be an A to B that does combine/split inputs and outputs. Once again more info required from the OP

It says "Sterling" and "Battery management system" on the read-out screen. Volts and amps are displayed (rather like on the solar controller) but I don't know if it does anything else. There is an adverc gizmo which I have always assumed was a split charge relay.

3 hours ago, Mike the Boilerman said:

 

One thing puzzling me here is why the Combi engine battery output would ever be wired up on a twin alternator boat. Surely the dedicated engine battery alternator will charge the engine battery just fine with no assistance from Mr Sterling's gubbins, just as it does on a car. 

On reflection, I don't actually understand what a 'combi' is!

That is, more or less, what the fitter said.

I think it's a "combi" of an inverter and a battery charger.

 

[WotEver]

2 hours ago, WotEver said:

I suspect that the ‘Sterling Battery Management’ thingy is their equivalent to a BMV. In other words an Ah counter with one or more shunts.

Not an alternator controller. 

But of course, I could be wrong. 

 

2 minutes ago, frahkn said:

It says "Sterling" and "Battery management system" on the read-out screen. Volts and amps are displayed (rather like on the solar controller) but I don't know if it does anything else.

So it is. 

3 minutes ago, frahkn said:

There is an adverc gizmo which I have always assumed was a split charge relay.

It’s an alternator controller, designed to give a greater output on older alternators with low voltage regulators. 

[frahkn]

2 hours ago, WotEver said:

The fact that whoever installed the battery monitor apparently didn’t run a wire from the starter battery up to it suggests to me that they might also not have bothered to wire the charger to the starter battery either. It makes little sense not to as it wouldn’t be a particularly fat cable and it would follow the same run as the main output but the reasons some folk do stuff has often escaped me. 

I might have a clue about this (see above) the domestic bank is close to the combi but the starter battery is a further 12 or so feet away - by the engine (which is in the bathroom).

[frahkn]

2 hours ago, Alan de Enfield said:

As I stated on the 'other thread', this method of wiring is not 'unusual', I have had two boats wired in such a fashion - why ? I have no idea.

The chargers commonly have the ability to charge 2 or 3 battery banks, and often an additional specific low-current (typically 5a) specific starter-battery output. The installers often / occasionally obviously just don't bother to connect them.

The Victron Centaur that recently burnt-out had 3 outputs, whilst its replacement, the Victron Phoenix has 2 outputs + A starter battery output.

But it is important to remember that the charger output is split across the number of outputs (except for the starter output which is separate)

 

 

Thank you.

I though this was what you meant in the other thread but someone suggested that there was no divergence of opinion and I got confused.

I am reassured that a (admittedly non-expert) fitter, who I trust, was not making it up as he went along.

[frahkn]

8 minutes ago, WotEver said:

 

So it is. 

It’s an alternator controller, designed to give a greater output on older alternators with low voltage regulators. 

Right.

So the Sterling kit is not a split charge device (I never thought it was) and now I know that the adverc is not either.

So either I don't have one or it is some where else between the batteries and the alternators. See what I mean about not knowing my own boat well enough.